Please forgive me if these ideas have been mentioned. I did try searching before I posted this, but it's a HUGE thread and I just couldn't read every single page.
Overall, I absolutely love Civ5, but the one area I continually find frustrating is worker control. I know, to hardcore players worker automation is unspeakable, but micromanaging gets TEDIOUS. What really frustrates me is that Civ3 gave you pretty granular control over worker automation, letting you choose on a per-worker basis whether to automate the whole empire vs just one city, whether to build over existing improvements, whether to chop, etc. Civ4 also had an option to tell a worker to "Build Trade Network", so he would just be connecting cities and improving resource tiles. I used to use that option A LOT, because I could let the automated workers focus on that, and then micromanage the terrain improvements based on my specific needs for each city.
Redox developed a VERY nice mod he calls "Light Touch" which will let you assign a worker to improve around a single city, improving those tiles only.
http://forums.civfanatics.com/showthread.php?t=426849&highlight=light+touch But there are two other forms of worker automation I would LOVE to see added in via mod.
1) Re-introduce the "trade network" automation in some form. I envision this as either telling a worker to just roam the empire connecting cities, or in a similar way to Light Touch, point the worker at one city and tell him to build roads to all the neighboring cities.
2) I would LOVE to see an option for a military unit to "escort" a worker/settler(I'm pretty sure I'm not the first one to suggest this). The last few games I've been playing, I've had a real problem with barbarians showing up in the early game and encroaching on my territory to capture workers. I'd be happy with either a "passive" escort(just staying on the same tile as the worker to discourage capture), or "active" escort(auto-attacking any barbarians or units belonging to civs I'm at war with).
I do have some coding experience, so I suppose with enough time and research I could learn how to do these myself, but I just don't have that kind of time in my schedule these days